Learning the molecular and cellular mechanisms required for pancreatic development has significant clinical implications. The overall goal of my work is to determine the mechanisms required for specification of the exocrine and endocrine pancreas in zebrafish. Specifically I will be fate-mapping the exocrine and endocrine pancreas and determining downstream targets of retinoic acid in the endocrine pancreas specification pathway. Previous work has shown that the pancreatic precursors come from distinct populations during early gastrulation. I will be determining whether those populations are separate endocrine and exocrine precursor populations. In this aim, I will also describe migration patterns of the pancreatic precursor cells. The second aim of my study will test whether tcf2 and hb9 are downstream targets of retinoic acid in specifying beta-cells. This study will provide further information on the early specification of the pancreas. One of the goals in diabetes research is to have stem cell populations differentiate into functioning islets for transplantation. Learning more about the molecular signals necessary for early pancreatic specification will provide further clues of signals needed for stem cell differentiation.